We propose to evaluate techniques, based on digital processing of conventional and specialized image intensified fluoroscopic television images, for potential applications in the screening of patients at risk for extracranial atherosclerotic disease of the carotid arteries. Preliminary feasibility studies have indicated that images of useful resolution and contrast can be obtained using intravenous iodinated contrast medium injections on the order of .6 cc/kgm. The study will involve comparison of images obtained by intravenous angiographic studies with those obtained from conventional angiography. Surgical results, and when available, post-mortem results will also be correlated with the images obtained by intravenous angiographic studies.